Field of the Invention
The present invention relates to the field of custom knee braces and the manner in which such knee braces are produced in particular.
Description of Related Art
Custom knee braces, i.e., knee braces that have been made to fit a leg of a specific person, have been made have been made from a hand-modified positive model (filled cast) of a patient's leg. That is, to order a custom knee brace, the doctor would make a negative casting of the patient's leg and send it to the knee brace manufacturer with an order for the type of brace desired. The knee brace manufacturer would use the negative casting to make a positive model of the patient's leg to which the custom brace would be fit. There are significant costs associated with taking and shipping a cast mold, and with health insurance reimbursements declining and expenses increasing a need has arising for a less costly way of obtaining a custom knee brace.
In recent years, various devices for 3D printing of three dimensional solid objects from a digital model using additive processes have been developed. 3D printers create an object by laying down successive layers of material. The machine reads in data from a CAD drawing and lays down successive layers of liquid, powder, or sheet material, and in this way builds up the model from a series of cross sections. These layers, which correspond to the virtual cross section from the CAD model, are joined together or fused automatically to create the final shape. Examples of 3D printers can be found, e.g., in U.S. Pat. Nos. 8,175,734; 8,119,053; and 7,291,002 among very many others. This technology is used in the fields of jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automotive, aerospace, dental and medical industries, education, geographic information systems, civil engineering, and many others. U.S. Pat. No. 7,756,325 discloses an algorithm for estimating the 3D shape of a 3-dimensional object, such as a human face, based on information retrieved from a single photograph by recovering parameters of a 3-dimensional model as well as methods and systems using same. Beside the pixel intensity, the invention uses various image features in a multi-features fitting algorithm (MFF) that has a wider radius of convergence and a higher level of precision and provides thereby better results. However, to date, a method of using 3D printer technology to create custom knee braces has not existed, at least in part, due to the lack of a means of obtaining a usable image.